A stingray perhaps?

RE putting your foot into hot water and the pain subsiding... while I am not a doctor I assume this could be due to the the toxins (assuming any where involved in this incidence) are being broken down by the heat of the water.

was the sting on top of your foot or underneath?

Stood on a flathead once, and I've seen a few people spiked by guernards, similar symptoms. Most marine creatures have some form of defense mechanism.

Also, you mentioned that you were in the weedy area, possibly a type of coral also...there would be many 'creatures' that would cause that sting. Also, the algae & bacteria in the water alone could cause that sort of pain if exposed to an open wound.

i think the hot water only isolates the venom, so when the temperature reverts to normal the pain starts again as the toxins start moving around again..

aquaplane said...

i think the hot water only isolates the venom, so when the temperature reverts to normal the pain starts again as the toxins start moving around again..

I think you'd find the opposite- heat causes vasodilation, the capillaries open up and the blood flow is greater. That is why you go red if dunkeing bits in hot water.

So the heat breaks down the venom as stated, but maybe the increased blood flow moves it away faster so it is metabolised elsewhere in the body

theres a fish we used to call "poor mans lobster" which is kinda like a stone fish but pinky / red and hangs around weed & rocks. has a small spine on the back of its head.
has a similar protein based venom it injects.
if you step on one, you need to do the hot water treatment asap as in yesterday and itll stop it pretty quick.
when spearfishing on the east coast, when desperate, we used to eat them and theyre not bad but boney.
mate of mine stepped on one in the low tide wash zone on sand. said they hurt like hell.

Well I got stung by my fifth cobbler tonight so I'm getting a bit of practical experience with dealing with it.

Wheat heat packs are vastly superior to buckets of hot water, less chance of burns and a lot easier to move around

Air activated heat packs (available from chemists) can be adhered to the bottom of your foot and worn in shoes / boots and will also alleviate the pain, they also last for around 8 hours.

KenHo said...

My old book "Dangerous MArine Animals of the Indo-PAcific region" by Carl Edmonds would have the answer in it.

Things like bull-rout etc, I think will give stings like this.
Similar to a stone-fish, but much less severity.

Don't have it with me.

Nah, experienced the joy of these as a kid- they say people dont remember pain, you never forget these if it a good sting. Initially it like 13 hypodermic needles going into foot then very intense sharp pain. Then it gets worse, i couldnt walk on that foot. Then just lots of pain for 4-6hrs, whole foot & half of lower leg swell up many times size of other foot. You wouldnt be sailing after stepping on one.

Couldve been anything, so many fish & corals will give an annoyingly painful sting for several hours.

stehsegler said...

adamhatfield said...
Only thing I thought it could be was a bull rout, but no idea if thats the case.

Just googled that... man that's one fuggly fish.

Think they are freshwater fish. I caught one on a lure one day when I was fishin for barra back home. Ugly as a hat full of as s holes

I stood on a bullrout once years ago at Valentine.I kept sailing and noticed the pain a bit but @## the pain was bad when I stopped and I didnt have any adrenaline going on..

fortescue

KenHo said...

Close, but contains a few errors.
A protein depends on it's shape to be active. The shape is determined by the polypeptide sequence.
When a protein is denatured by heat or a few other things, it loses it's shape, and becomes inactive. If it returns to normal temperature, it regains it's shape, if the sequence is intact, which accounts for the return of pain.
Denaturing is not like scrambling an egg.

We could get into a very nerdy debate here.

As you are aware, the protein consists of a long polypeptide chain (or chains). This chain is then folded onto itself in a complex way to give the protein its "shape", referred to as secondary, tertiary, and quaternary structure. It is held in this shape by quite weak bonds (such as hydrogen bonds, salt bridges, non-polar hydrophobic interactions).

Heat and other insults (e.g. acids) breaks these weak bonds and allows the protein to unfold (i.e. change its shape). This occurs without breaking the polypeptide sequence or chain (which is held together by stronger covalent bonds). New bonds then form which hold it in this new shape even when the temperature returns back to normal. The shape of the protein molecule has changed but its polypeptide sequence has not. This process is called denaturation.

To reverse this denaturation requires energy to break these weak bonds again and also a replication of the conditions under which the protein was first formed inside the fish cell (e.g. temperature, pH, concentrations of various electrolytes, other solutes, plus/minus enzymes). Without these specific conditions, even with the application of energy to get over the unfavorable kinetics, the protein will not return to its original shape.

Hence denaturation (=change in shape) by heat is usually irreversible. The egg being an obvious example.

However, might it be conceivable that with very low heat only a couple of the weakest bonds break, leaving almost all of the "shape" intact so that it could possibly return back to its original "shape" spontaneously? Such a minor loss in shape might be just enough if it were to occur at the right place for it not to be able to interact with whatever it needs to in the foot (such as bind to pain receptors, or act as an enzyme to catalyze a specific reaction).

There would be a whole heap of other plausible sounding explanations of how heat changes the multiple biological processes that occur in the foot that finally result in the activation of pain nerve fibres.

I think we simply don't know for sure.